Age of the uterus does not affect pregnancy or implantation rates; a study of egg donation in women of different ages sharing oocytes from the same donor.

The importance of age of the recipient (uterine age) with regards to pregnancy rate, delivery rate and miscarriage rate following oocyte donation was evaluated using retrospective data analysis of cases where two recipients from different age groups shared oocytes from a single donor and had equal numbers of embryos transferred. A total of 104 women (21-52 years of age) underwent a total of 104 cycles of oocyte donation. They were divided into groups according to age (group A: age 39 years or less and group B: age between 40 and 52 years). The minimum age difference between a pair of recipients was five years. Hormone replacement therapy (HRT) was given using oestradiol valerate (6 mg daily) for at least 10 days, followed by a combination of oestradiol with either intramuscular progesterone (100 mg daily), or vaginally administered micronized progesterone (300 microg daily). Women with ovarian function received down-regulation using a luteinizing hormone-releasing hormone (LHRH) analogue before hormone replacement was commenced. A total of 52 transfer cycles was performed in each age group and pregnancy, delivery and miscarriage rates were analysed as outcome measures; 20 pregnancies were achieved in each group (an identical pregnancy rate of 38.5%). In group A seven pregnancies miscarried out of 20 (35%), which was not significantly different from the rate in the older population, group B, where eight out of 20 pregnancies miscarried (40%). The delivery rate in group A was 25% (13 out of 52), again not significantly different from the delivery rate in group B of 23.1% (12 out of 52). In conclusion, using egg donation as a model, the decline in fecundity with age cannot be explained by uterine factors alone.